headache tree
noun
1A tropical shrub, Premna serratifolia (family Lamiaceae (Labiatae)), widely occurring in coastal Asia and the Pacific Islands, the leaves of which are used to treat headaches (now rare ).
2The California laurel, Umbellularia californica, whose leaves when crushed have a pungent smell that supposedly causes headaches.
Origin
Mid 19th century; earliest use found in Robert Hogg (1818–1897).